Übergangsmetallkomplexe von Diazenen, XXIV [1]. Komplexierung und N=N-Spaltung von Diazenen durch Dicarbonylbis(cyclopentadienyl)titan / Transition Metal Complexes of Diazenes, XXIV [1] Complexation and N = N-Cleavage of Diazenes by Dicarbonylbis(cyclopentadienyl)titanium

Abstract

Reaction of Cp2Ti(CO)2, Cp=h5-C5H5, with the 1,2-diazenes ROCN = NCOR (R = EtO (1a), tert-BuO (1b), p-MeC6H4O (1c), p-MeC6H4 (1d)) in the molar ratio of 1:1 yiclds five- membered metallacycles 2 by formal 1,4-addition of 1 to the Cp2Ti fragment. When a two-fold excess of Cp2Ti(CO)2 is employed, the initially formed 2 reacts further by N = N-cleavage to give Cp2Ti(NCO)(OR), Cp2Ti(NCO)2 and Cp2Ti(OR)2 resp., in the case of 1a-1c. The bis(p-methyl- benzoyI)diazene (1d) does not afford analogous cleavage products. Dimethyl- and pentamethy- lenediazirine also react by cleavage of the N = N-bond to afford Cp2Ti(NCO)(N=CR2).